As an adaptive control of an array weight in a transmission frequency band performed by a wireless communication apparatus having a plurality of antennas, there is a method to calculate the array weight by estimating a channel coefficient in the transmission frequency band by an extrapolation process such as a linear extrapolation based on a distribution of the channel coefficients in a reception frequency band in a direction of frequency (for example, Patent Document 1). More specifically, when a reception channel coefficient (absolute value) changes from a point p11 to a point p12 shown in FIG. 10, it is estimated (calculated) that a transmission channel coefficient (absolute value) is at a point p13 in FIG. 10, based on the change of the reception channel coefficient.
Patent Document 1: Japanese Patent No. 3644594